1. Field of the Invention
The present invention relates to a method, an apparatus, and a computer program for controlling use of a content under a predetermined usage condition, and, in particular, to a method, apparatus, and a computer program for controlling use of a content provided to a user via a network or the like.
More particularly, the present invention relates to a method, an apparatus, and a computer program for controlling use of a content acquired via a network or the like under the control of a specific server manager, and, in particular, to a method, an apparatus, and a computer program for controlling use of a content managed by an end user so that the content is prevented from being illegally used.
2. Description of the Related Art
Nowadays, highly advanced technology is available in information processing, information communication, and computing, and computer systems are used in a wide variety of applications. There is an increasing need for network computing technology to connect computers to each other. In an environment in which computers are connected to each other via a network, computer resources can be shared by users and a job can be executed in a cooperative manner. Furthermore, information contents can be shared, distributed, and exchanged smoothly.
In recent years, widespread use of the Internet, advances in high-speed accessing technology such as broadband networking technology, and reduction in const have made it possible for many users to easily transmit various kinds of information contents over the world.
However, a problem of copyright protection has arisen, because distribution systems, such as Napster or Gnutell, have appeared which illegally copy and distribute copyrighted content data such as movie or music content data. Networks will be used in an increasingly wider scale and the performance thereof will be increasingly more enhanced. However, high values of such highly advanced networks will not be actually useful unless a mechanism of preventing contents from being illegally used will be established, because only limited information will be transmitted in an environment in which copyright is not protected. Furthermore, unauthorized use of contents will reduce motivation of writers or providers of contents, and related business will be greatly damaged.
In distribution of contents via a wide area network such as the Internet, in general, copyright is technically protected by distributing contents only when it is assured that the contents are used by authorized users or when charging for use of the contents has been performed.
In recent years, private networks such as a home network have become popular. Users are allowed to distribute contents within their home as long as the copyright of contents is not infringed. For example, a content acquired via BS digital broadcast may be distributed among information devices connected to each other via i-Link or the like. In such usage of contents, end users have to protect the contents. However, in such usage of contents, there is a possibility that contents are distributed to the outside of home without limitation.
To prevent such a possibility in a system in which contents such as a movie content or a music content purchased by a user are stored in a home server and viewed or listened to via the Internet, it is required to establish a mechanism of preventing the contents from being accessed for purposes departing from the private use.
However, at present, there is no standard copyright protection system widely accepted by copyright holders. In the USA, because of lack of consensus on protection of copyright of contents, there are lawsuits for broadcast recording apparatuses having the capability of transmitting contents via the Internet.
One known technique of preventing contents from being used illegally in departure from personal use is to limit the number of devices which can receive service. Another known technique is to limit access of contents such that only those clients whose identification information (such as a MAC address) has already been registered are allowed to access contents. However, those techniques are effective if server managers correctly perform settings and if server manages do not intentionally make setting such that illegal access becomes possible. From the viewpoint of content copyright holders, even in a case in which contents are managed by a server manager, in particular, by an end user of a home server or the like, it is necessary to prevent contents from being illegally distributed. However, at present, there are no standard protection mechanisms or systems which satisfy the above requirement.